Field of the Invention
The present invention relates to a piezoelectric device.
Related Background Art
As a conventional piezoelectric device, for example, a piezoelectric device disclosed in Japanese Patent Application Laid-Open No. 2012-182567 is known. The piezoelectric device disclosed in Japanese Patent Application Laid-Open No. 2012-182567 includes an element mounting member having a substrate part, a first frame part provided on one main surface of the substrate part, and a second frame part provided on one main surface of the first frame part; a thermistor element provided on the main surface of the substrate part exposed within a second recessed space formed by the substrate part and the first frame part; a piezoelectric vibration element provided on the main surface of the first frame part exposed within a first recessed space formed by the first frame part and the second frame part; and a lid hermetically sealing the first recessed space and the second recessed space.
The above-described piezoelectric device measures a temperature of the piezoelectric vibration element (an ambient temperature of the piezoelectric vibration element) with the chip-shaped thermistor element arranged within the recessed space along with the piezoelectric vibration element. The piezoelectric vibration element is configured with excitation electrodes arranged on both main surfaces of a crystal plate. Heat from the outside (for example, a circuit substrate or the like on which the piezoelectric device is mounted) of the piezoelectric device is transferred to the piezoelectric vibration element via a conductor or the like arranged on the substrate part. At this time, because the piezoelectric vibration element and the thermistor element have significantly different shapes and also have different areas (volumes) of electrodes (metals), heat capacity is different. Thus, in the conventional piezoelectric device, a difference between a real temperature of a piezoelectric vibration element and a measured temperature measured by the thermistor element may occur.
An objective of the present invention is to provide a piezoelectric device capable of improving the measurement precision of a temperature of a piezoelectric element.